FLINT3.7.0-dev

arb_hypgeom_central_bin_ui

Synopsis#include <flint/arb_hypgeom.h>
void arb_hypgeom_central_bin_ui(arb_t res, ulong n, slong prec)source

Sets res to the central binomial coefficient \binom{2n}{n}.

For n \le 17 the value comes from a table and for n < 6\,\mathit{prec} + 200 from the exact integer fmpz_bin_uiui. For larger n the function sums the asymptotic expansion of \binom{2n}{n} \sqrt{\pi n} / 4^n in powers of 1/n^2, whose coefficients involve Bernoulli numbers, with the rigorous error bound of Brent [Bre2016].

References#

Cite this page

The FLINT team, “arb_hypgeom_central_bin_ui (arb_hypgeom.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/arb_hypgeom/arb_hypgeom_central_bin_ui.html (generated 2026-10-20).